Contingencies - Environmental Contingencies (Details)	9 Months Ended
Sep. 30, 2020 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Environmental liability insurance, maximum coverage per incident (up to)	$ 10,000,000
Environmental liability insurance, annual coverage limit (up to)	$ 50,000,000

Annual coverage limit provided by the insurance arrangement for environmental liability claims.

No definition available.

Name:	cbl_EnvironmentalLiabilityInsuranceAnnualCoverageLimit.
Namespace Prefix:	cbl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration